PHY 712 Electrodynamics

MWF 11-11:50 AM Olin 103 Webpage: http://www.wfu.edu/~natalie/s22phy712/

Instructor: Natalie Holzwarth Office:300 OPL e-mail:natalie@wfu.edu



Course schedule for Spring 2022

(Preliminary schedule -- subject to frequent adjustment.)
Lecture date
JDJ Reading
Topic
HW
Due date
1 Mon: 01/10/2022 Chap. 1 & Appen. Introduction, units and Poisson equation #1 01/14/2022
2 Wed: 01/12/2022 Chap. 1 Electrostatic energy calculations #2 01/19/2022
3 Fri: 01/14/2022 Chap. 1 Electrostatic energy calculations #3 01/21/2022
Mon: 01/17/2022 MLK Holiday -- no class
4 Wed: 01/19/2022 Chap. 1 & 2 Electrostatic potentials and fields #4 01/24/2022
5 Fri: 01/21/2022 Chap. 1 - 3 Poisson's equation in 2 and 3 dimensions #5 01/26/2022
6 Mon: 01/24/2022 Chap. 1 - 3 Brief introduction to numerical methods #6 01/28/2022
7 Wed: 01/26/2022 Chap. 2 & 3 Image charge constructions #7 01/31/2022
8 Fri: 01/28/2022 Chap. 2 & 3 Cylindrical and spherical geometries #8 02/02/2022
9 Mon: 01/31/2022 Chap. 3 & 4 Spherical geometry and multipole moments #9 02/04/2022
Wed: 02/02/2022 No class Fire caution
Fri: 02/04/2022 No class Fire caution
10 Mon: 02/07/2022 Chap. 4 Dipoles and Dielectrics #10 02/09/2022
11 Wed: 02/09/2022 Chap. 4 Dipoles and Dielectrics #11 02/11/2022
12 Fri: 02/11/2022 Chap. 5 Magnetostatics #12 02/14/2022
13 Mon: 02/14/2022 Chap. 5 Magnetic dipoles and hyperfine interaction #13 02/16/2022
14 Wed: 02/16/2022 Chap. 5 Magnetic dipoles and dipolar fields #14 02/18/2022
15 Fri: 02/18/2022 Chap. 6 Maxwell's Equations
Mon: 02/21/2022 Chap. 1-6 Homework review & and presentations
16 Wed: 02/23/2022 Chap. 6 Electromagnetic energy and forces #15 02/25/2022
17 Fri: 02/25/2022 Chap. 7 Electromagnetic plane waves #16 02/28/2022
18 Mon: 02/28/2022 Chap. 7 Electromagnetic plane waves #17 03/02/2022
19 Wed: 03/02/2022 Chap. 7 Optical effects of refractive indices
20 Fri: 03/04/2022 Chap. 8 Brief introduction to wave guides
Mon: 03/07/2022 No class Spring Break
Wed: 03/09/2022 No class Spring Break
Fri: 03/11/2022 No class Spring Break
Mon: 03/14/2022 No class APS March Meeting Prepare Project
Wed: 03/16/2022 No class APS March Meeting Prepare Project
Fri: 03/18/2022 No class APS March Meeting Prepare Project
Mon: 03/21/2022 Project presentations I
Wed: 03/23/2022 Project presentations II
21 Fri: 03/25/2022 Chap. 9 Radiation from localized oscillating sources #18 03/30/2022
22 Mon: 03/28/2022 Chap. 9 Radiation from oscillating sources
23 Wed: 03/30/2022 Chap. 9 & 10 Radiation and scattering #19 04/01/2022
24 Fri: 04/01/2022 Chap. 11 Special Theory of Relativity #20 04/04/2022
25 Mon: 04/04/2022 Chap. 11 Special Theory of Relativity #21 04/06/2022
26 Wed: 04/06/2022 Chap. 11 Special Theory of Relativity
27 Fri: 04/08/2022 Chap. 14 Radiation from moving charges #22 04/11/2022
28 Mon: 04/11/2022 Chap. 14 Radiation from accelerating charged particles #23 04/18/2022
29 Wed: 04/13/2022 Chap. 14 Synchrotron radiation
Fri: 04/15/2022 No class Holiday
30 Mon: 04/18/2022 Chap. 14 & 15 Thompson and Compton scattering #24 04/20/2022
31 Wed: 04/20/2022 Chap. 15 Radiation from collisions of charged particles
32 Fri: 04/22/2022 Chap. 13 Cherenkov radiation
33 Mon: 04/25/2022 Special topic: E & M aspects of superconductivity
34 Wed: 04/27/2022 Review
35 Fri: 04/29/2022 Review


PHY 712 -- Assignment #1

January 10, 2022

Read Chapters I and 1 and Appendix 1 in Jackson.

  1. Jackson Problem #1.5. Be careful to take into account the behavior of Φ(r) for r-->0.

PHY 712 -- Assignment #2

January 12, 2022

Continue reading Chap. 1 in Jackson.

Calculate the electrostatic energy of the following 5 ion molecule scaled by the factor (1/(4πε0)) (q2 / a). Note that x, y, and z denote unit vectors in the three Cartesian directions.

  1. Charge = 4q   Position = 0
  2. Charge = -q   Position = (a/2)(x+y+z)
  3. Charge = -q   Position = (a/2)(-x-y+z)
  4. Charge = -q   Position = (a/2)(x-y-z)
  5. Charge = -q   Position = (a/2)(-x+y-z)

PHY 712 -- Assignment #3

January 14, 2022

Continue reading Chap. 1 in Jackson.

  1. Using the Ewald summation methods developed in class, find the electrostatic interaction energy of a NaCl lattice having a cubic lattice constant a. Check that your result does not depend of the Ewald parameter η. You are welcome to copy (and modify) the maple file used in class. A FORTRAN code is also available upon request.


PHY 712 -- Assignment #5

January 21, 2022

Continue reading Chap. 1-3 in Jackson.

  1. For the two-dimensional rectangular system discussed in the lecture notes, work out the analytic form of the electrostatic potential Φ(x,y) for the following charge density for 0 ≤ x ≤ a and 0 ≤ y ≤ b. Assume that the potential is 0 on the boundary of the rectangle.

    ρ(x,y)= ρ0 sin(πx/a) sin(πy/b)

    Here ρ0 is a given constant. (Note there is an easy way and a hard way to solve this problem.)


PHY 712 -- Assignment #6

January 24, 2022

Continue reading Chap. 1-3 in Jackson.

  1. For a two-dimensional square system, work out the analytic form of the electrostatic potential Φ(x,y) for the following charge density for 0 ≤ x ≤ a and 0 ≤ y ≤ a. Assume that the potential is 0 on the boundary of the square.

    ρ(x,y)= ρ0 sin(πx/a) sin(2πy/a)

    Here ρ0 is a given constant having units of charge/volume. (Note that this is almost identical to HW #5.)

  2. Now, using the finite difference of finite element method for the two grids discussed in class, find Φ(x,y) on the grid points and compare the numerical solutions with the exact answer.


PHY 712 -- Assignment #7

January 26, 2022

Continue reading Chap. 2 in Jackson.

  1. Eq. 2.5 was derived as the surface change density on a sphere of radius a due to a charge q placed at a radius y > a outside the sphere. Determine the total surface charge on the sphere surface.
  2. Now consider the same system except assume y < a representing the charge q being placed inside the sphere. What is the surface charge density and the total surface charge in this case?

PHY 712 -- Assignment #8

January 28, 2022

Finish reading Chap. 2 and start Chap. 3 in Jackson.

  1. Consider the long cylindrical shell charge density discussed in Lecture 8, confirming the the electrostatic potential and also calculating the electrostatic field for this system.

PHY 712 -- Assignment #9

January 31, 2022

Complete reading Chapter 3 and start Chapter 4 in Jackson .

  1. Consider the charge density of an electron bound to a proton in a hydrogen atom -- ρ(r) = (1/πa03) e-2r/a0, where a0 denotes the Bohr radius. Find the electrostatic potential Φ(r) associated with ρ(r). Compare your result to HW#1.

PHY 712 -- Assignment #10

February 7, 2022

Continue reading Chapter 4 in Jackson .

  1. Find the monopole, dipole, and quadrupole moments of the charge distribution shown in the figure in problem 4.1(b) of Jackson. You can use either the Cartesian or spherical polar forms for the moments as you prefer.

PHY 712 -- Assignment #11

February 9, 2022

Finish reading Chapter 4 in Jackson .

  1. Work problem 4.9(a) in Jackson. It is probably most convenient to use a coordinate system with the origin at the center of the dielectric sphere.

PHY 712 -- Assignment #12

February 11, 2022

Start reading Chapter 5 in Jackson .

  1. Consider an infinitely long cylindrical wire with radius a, oriented along the z axis. There is a steady uniform current inside the wire. Specifically, in terms of r the radial parameter of the cylindrical coordinates of the system the current density is J(r)=J0 , where J0 is a constant vector pointing along the z-axis, for ra and zero otherwise.
    1. Find the vector potential (A) for all r.
    2. Find the magnetic flux field (B) for all r.

PHY 712 -- Assignment #13

February 14, 2022

Continue reading Chapter 5 in Jackson .

  1. Work problem 5.13 in Jackson.

PHY 712 -- Assignment #14

February 16, 2022

Finish reading Chapter 5 in Jackson .

  1. Work through some of the details of magnetic shielding effects of the highly permeable spherical shell given in Eq. 5.121 of Jackson and/or the equivalent presentation in the lecture notes.

PHY 712 -- Assignment #15

February 23, 2022

Finish reading Chapter 6 in Jackson .

  1. From the definitions of the Poynting vector S and Maxwell stress tensor Tαβ given in Chapter 6, determine their units for each in terms of fundamental SI variables.

PHY 712 -- Assignment #16

February 25, 2022

Start reading Chapter 7 in Jackson .

  1. Consider the reflectivity of a plane polarized electromagnetic wave incident from air (n=1) on a material with refractive index n'=1.5 at an angle of incidence i. Assume μ=μ'. Plot the reflectance

    R(i)=|E"0/E0|2

    as a function of i for 0 ≤ i ≤ 90 deg for both cases of polarization of (E0 in the plane of incidence or perpendicular to the plane of incidence). What is the qualitative difference between the two cases?

PHY 712 -- Assignment #17

February 28, 2022

Continue reading Chapter 7 in Jackson .

  1. Work problem 7.22 (a) in Jackson.

PHY 712 -- Assignment #18

March 21, 2022

Start reading Chapter 9 in Jackson .

  1. Problem 9.10 in Jackson lists the harmonic frequency denpendent charge and current densities of a radiating H atom. Instead of answering Jackson's questions, calculate the exact scalar Φ(r) and vector potential A(r) fields for r>>a0 and compare your results with the scalar and vector potential fields calculated within the dipole approximation.

PHY 712 -- Assignment #19

March 30, 2022

Finish reading Chapters 9 and 10 in Jackson .

  1. Work problem 9.16(a) in Jackson. Note that you can use an approach similar to that discussed in Section 9.4 of the textbook, replacing the "center-fed" antenna with the given antenna configuration.

PHY 712 -- Assignment #20

April 1, 2022

Start reading Chapters 11 in Jackson .

  1. In class, we examined measurements of quantities that could be measured in two different reference frames which were related by the Lorentz transformation matrix. In particular, we are interested in the velocity components such as ux and and u'x. For the geometry used in class, work out the algebraic relationships that show that the 4-components of the vector (γuc, γuux, γuuy, γuuz) are related by a Lorentz transformation to the corresponding 4-component vector measured in the moving frame -- (γu'c, γu'u'x, γu'u'y, γu'u'z).

PHY 712 -- Assignment #21

April 4, 2022

Continue reading Chapter 11 in Jackson .

  1. Derive the relationships between the component of the electric and magnetic field components E1, E2, E3, B1, B2, and B3 as measured in the stationary frame of reference and the components E'1, E'2, E'3, B'1, B'2, and B'3 measured in the moving frame of reference. Note that the reverse relationships are given in Eq. 11.148.

PHY 712 -- Assignment #22

April 8, 2022

Start reading Chap. 14 in Jackson .

  1. Consider an electron moving at constant speed βc ≈ c in a circular trajectory of radius ρ. Its total energy is E= γ m c2. Determine the ratio of the energy lost during one full cycle to its total energy. Evaluate the expression for an electron with total energy of 200 GeV in a synchroton of radius ρ=103 m. Note if you use, the analysis of Jackson, please explain the details.

PHY 712 -- Assignment #23

April 11, 2022

Continue reading Chap. 14 in Jackson . This problem is designed to demonstrate Parseval's theorem using the definitions given in the lecture notes and on Page 674 in Jackson. We will use the example

A(t)=K e-(t/T)2,

where K and T are positive constants.

  1. Find the Fourier transform of A(t).
  2. Evaluate the integral of the squared modulus of A(t) between -∞ ≤ t ≤ ∞.
  3. Evaluate the integral of the squared modulus of the Fourier transform of A(t) between -∞ ≤ ω ≤ ∞.

PHY 712 -- Assignment #24

April 18, 2022

Finish reading Chap. 14 and start Chap. 15 in Jackson .

  1. This problem concerns the Compton scattering of a photon having an initial momentum magnitude of p and a final momentum magnitude p' at an angle θ due to an electron of mass m, initially at rest, as discussed in lecture and on page 696 of Jackson. The wavelength of the photon before the collision is λ=h/p and after is λ'=h/p', where h is Planck's constant. Show that

    λ'-λ=(h/(mc))(1-cosθ).




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Last modfied: Wednesday, 05-Jan-2022 11:22:08 EST